Make sure we don't run the role on neovim configured with init.vim

roles/neovim/tasks/main.yml

@@ -1,4 +1,10 @@
 ---
+- name: Fail if still using init.vim
+  stat:
+    path: ~/.config/nvim/init.vim
+  register: init_vim
+  failed_when: init_vim.stat.exists
+
 - name: Install (Archlinux)
   block:
     - name: Install packages (Archlinux)